Men at age 41 who had ADHD in childhood had significantly higher BMI (30.1 versus 27.6, P=0.001) and rates of obesity (41.4% versus 21.6%, P=0.001) compared with men who did not have ADHD when they were young, according to F. Xavier Castelanos, MD, of NYU Langone Medical Center in New York, N.Y., and colleagues.

These associations persisted after adjustment for socioeconomic status and lifetime mental disorders, they wrote online in Pediatrics.

Prior cross-sectional research in children and adults has found a significant link between ADHD and obesity, though these associations have not been examined past adults' final growth period, they noted.

"We are paying attention to obesity more and more these days. It would make a lot of sense to perhaps emphasize that issue with boys who have ADHD as they move into adulthood, no matter what," Charles Shubin, MD, of Mercy Medical Center in Baltimore, Maryland, told MedPage Today.

"We would want to pay attention to anybody who's at risk for obesity and hopefully manage it," added Shubin, who was not involved in the study.

The study examined BMI and obesity in adult men with and without ADHD, with persistent and with remitted ADHD, with remitted or persistent ADHD, and without ADHD in a population of 111 white men with childhood ADHD and 111 age-, parental social class-, and geographic residence-matched men without ADHD.

Participants with ADHD were included based on school referral due to behavior problems, had elevated hyperactivity ratings by teachers and parents, had an IQ of 85 or greater, were from English-speaking parents, and were age 6 to 12 (mean age 8.3) at enrollment.

Follow-up was conducted at mean ages 18.4, 25, and 41.2. Additionally, the healthy, matched control group was recruited at age-18 follow-up.

Data were collected on ADHD status at age 41, as were substance and mental disorders, BMI from self-reported height and weight, parental socioeconomic status, and participants' adult socioeconomic status.

Ongoing ADHD was defined as DSM-IV symptom criteria over the previous 6 months, ADHD symptoms causing clinically significant functional impairment, and symptoms not accounted for by another disorder.

Participants without childhood ADHD had significantly higher parental and current socioeconomic status (P=0.03 and P<0.001, respectively), and had significantly lower rates of non-alcohol substance use disorders and nicotine dependence (P=0.02 and P<0.001, respectively). Rates of lifetime mood and anxiety disorders did not differ significantly between groups, nor did height.

Those who had childhood ADHD had greater mean weight (212.6 versus 193.8, P=0.001), BMI (30.1 versus 27.6, P<0.001), and rates of obesity (41.4% versus 21.6%) than those without childhood ADHD. These differences remained significant after adjusting for parental socioeconomic status and lifetime mental disorders.

In a comparison of those with persistent- and remitted-ADHD, weight (199.5 versus 216.1, P<0.001) and BMI (28.9 versus 30.4) were greater in those with persistent- versus remitted-ADHD, as were rates of overweight (12% versus 31%) and obesity (7% versus 39%).

Compared with those without childhood ADHD, those with persistent ADHD did not differ significantly in rates of obesity or BMI, while those with remitted ADHD did have significantly higher rates of obesity and higher BMI (P<0.001 for both).

Shubin noted that ADHD drugs come with a warning about appetite suppression and cautioned that this was not an effect analyzed in this study, but which may account for the differences in weight in adulthood between groups.

The authors also noted that their study was limited by missing weight and height for some of the cohort and a limited number of subjects with persistent ADHD. The study was also limited by a missing evaluation of participants' physical activity, sedentary time, and sleep problems.

The study was supported by the National Institute of Mental Health, the National Institute on Drug Abuse, and the International Outgoing Fellowship.

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